Pilot burner construction



July 26, 1938. F. A. GAUGER PILOT BURNER CONSTRUCTION Filed Feb. 27, 1937 INVENTOR. @7a/7?@ gaz/gaf' @w Zd- ATTORNEY.

Patented July 26, 1938 UNITEDV STATES PATENT' ori-ica 10 Claims.

`This invention relates to a. pilot burner construction. Objects of this invention are to overcome defects in pilot burner constructions as heretofore made, such as the extinguishing of 5 the flame from the pilot burner when the flame from the main burner iioats, or the extinguishing of the flame from the pilot burner due to the concussion from the main burner when the `main burner is lighted, and which also provides lo a pilot burner that is suitable for use either with artificial gas or with natural gas, and one that insures the safe and reliable lighting of the main burner under all conditions.

Further objects of this invention are to pro- 15 vide a pilot burner construction in which provision is made for the relative adjustment of a control member of the thermally responsive type for the control of the main burner, so that the relative position of the control member and the 0 pilot burner may be adjusted for'varying conditions of the fuel such as pressure, quality, natural gas or artiiicial gas or other variations of this type, so that the eiiicient functioning of the device may be assured under widely varying con- 5 ditions.

A further object is to provide a pilot burner construction in which the flame from the pilot burner that is used to light the main burner is the same flame that is employed to heat the control member, so that if the gas pressure should fall, the ilame from the pilot burner will not impinge onthe control member and thus the main burner will not be allowed to light and danger from explosions from delayed ignition will be minimized, and in which clogging of the pilot burner will always result in causing the control member to cut oi the fuel supply to the main burner as one and the same flame is used to both heat the control'member and light the main V burner, and thus there is not one flame or part of a flame from the pilot burner that lights the main burner and another flame or part of the iiame that heats the control member, which might result in heating of the control member y and not in the immediate lighting of the main burner.

Further objects are to provide a pilot burner construction which is suitable for use with either a thermo-couple type of control member or with other types oi control members, such as the ordinary thermostatic types for example, and in which the control member, no matter what type is used, is adjustable, preferably vertically, so as to compensate for dierences in gas pressure, in the quality of the gas, artificial or natural gas, and differences in the B. t. u. content, in which the air intake is located below the mixture zone, or in other words in the fresh air zone, so that even though the flame should iioat from the main burner, nevertheless the pilot burner will not be extinguished from this cause, and in which provision is made to prevent the extinguishing of the pilot burner from concussion at the time the burner is lighted.

A further object is to provide a burner shell that is freely removable and that lines up with the control member, preferably one that interlocks with or is guided by the control member,

so that although the burner shell is freely removable it will always have its outlet centered or aligned with the control member, and so that absolute freedom is provided for the cleaning of the burner shell and the nozzle of the pilot burner, the nozzle being itself removable from the body portion, and in which the control member may be removed or changed or vertically adjusted Without disturbing the pilot burner and without affecting the alignment of the outlet of the pilot burner with the control member.

Further objects are to provide a pilot burner in which a burner shell is provided and is so arranged that it is guided both at the top and at the bottom, in which the guiding means between the burner shell and body portion or between the burner shell and the nozzle are of poor thermal conductivity, in which there is no extra means to hold the shell in place, but in which the shell is merely placedover the nozzle and is held against shifting either at the top or bottom and is also held against turning, and in which there is an air inlet and a mixture outlet preferably provided in a concussion cup formed integrally with the burner shell. f Further objects are to provide a construction that is inexpensive to make, that is easy to keep clean, that has a small number of parts, and that is reliable in operation.

'I'his invention is an improvement over the inventions disclosed in my prior patents No. 1,960,777 of May 29, 1934, and No. 2,012,503 of August 27, 1935.

Embodiments of the invention are shown in the accompanying drawing, in which:

Figure l is a sectional elevation of the pilot burner, a portion of the main burner being shown.

Figure 2 is a front elevation of the pilot burner with parts broken away.

Figure 3 is a plan view of the pilot burner with the burner shell removed.

has been indicated. 'A fragment of the main burner is-shown in Figure 1 and indicated by the reference character 4 to show the relative position of the pilot burner and control member with respect to the mainburner.

The body portion is provided with an upstand- .ing .guiding and positioning integral portion which maybe circular in cross-section and may be provided with a pair of guiding ridges 5. 'Ihis upwardly projecting portion provided with the guiding ridges, receives the nozzle which may comprise a mixing element 6 having an air inlet passage 'I and a mixture outlet passage 8.

The nozzleimember may include a small, thin metal capsule-shaped nozzle proper .9 which has a small fuel discharge hole pricked therein by a needle and in alignment with the passage 8 'of the composite nozzle. 'I'hus the composite nozzle acts as a mixing member as the upwardly projecting small, rapidly flowing stream of gas entrains air through the passage 'I and mixes in the passage 8 and is discharged at the upper flaring end of the passage 8, see Figurel. The composite nozzle is screwed into the body portion I and is readily removable when the burner shell hereinbelow described is lifted from the device.

The burner shell may take any of many shapes but preferably comprises a cylindrical portion I which fits around the composite nozzle 6 and is spaced therefrom to provide an air chamber'l I between the composite nozzle and the shell I 0. The upper portion of the shell is provided lwith a concussion cup I2 and this concussion cup has a mixture outlet I3 from which the flame ls pro'- jected. It also is provided with one or more air inlet passages I, though it is to be distinctly understood that the air inlet passages may open outwardly at a point other than directly within the concussion cup I2. The preferred form, however, is as shown with the mixture outlet passage I3 and air inlet passage or passages I4 located in the concussion cup. This very definitely provides for equalizing the pressure both at the inlet and outlet passages when a concussion occurs due to the lighting of the main burner d.

The normal position of the pilot flame is indicated in dottedrlines at I and the position of the pilot flame when excessively low gas pressure exists is indicated by the reference character I6. The relative position of the ame under normal conditions with respect both to the thermally responsive control member 3 and the main burner 4 is the ame position I5, and it will be seen that the flame, before it arrives at the main burner, impinges on the control member 3 and thus it is impossible for the control member to be heated by the pilot flame unless the pilot flame is in a position suitable for lighting the main burner, thereby avoiding all chance of delayed lighting of the main burner with consequent violent explosions. It is to be noted that if the gas pressure drops to a point 'where the delayed ignition would occur due to the fact that the pilot flame does not reach to the main burner, this flame position I6 is such that the flame also fails to strike the control member 3 and thus the main burner would be automatically cut o, as the control member 3 controls the main burner in theusual and well known manner.

Additionally, if plugging or choking of the pilot flame outlet would occur, it would be impossible for the control member to be heated and yet not have the pilot flame in a position to lightv the main burner, for there is a single source for the pilot'flame for both allowing the heating of the control member and for lighting the main burner.

It is to be noted particularly that under different conditions of gas pressure obtaining in different cities and under other different conditions of the gas, for example natural or artificial gas, or a difference in the B.W t. u. content thereof, it is desirable to adjust the control member vertically to compensate for these differences. This is readily accomplished as the controlrmember 3 is held clamped in -position by means of the strap or other clamping member I'I, see Figures 2 and 3, this member II being held by means of the screws I 8, and thus providing for the ready ver= tical adjustment of the control member to secure the exact position required with respect to the pilot flame.

Additionally. it is to' be noted that means are provided for insuring the aligning of the pilot flame opening with the control member 3. This is secured in the particular form chosen for illustration by notching a portion of the peripheral flange ofthe concussion cup I 2, as indicated at I9, so that this notched portion is guided by the control member 3, but a slight clearance is allowed so that even if it does touch the control member, the thermal conductivity at this point is very poor. Additionally, it is desirable to min- Vimize the amount of heat that passes from'the burner shell to the composite nozzle 6 or the body portion I. This is secured by having a loose fit at the upper portion of the composite nozzle 6, which also acts as the upper guide for the burner shell, and between the annular ridges 5 of the body portion and the lower portion of th'e burner shell, and also by pointing or bevelling the lower edges of the burner shell itself, as indicated at 2Il in Figure l, so as to provide a pointed edge that loosely rests on the body portion I. All of these points of contact have very poor thermal conductivity and consequently a minimum of heat is transmitted either to the composite nozzle 6 or to the body portion I. This materially reduces the chance of clogging, irrespective of the type of gas supplied the pilot burner and additionally, particularly in the case where a thermo-couple control member is used, it is necessary to have a difference of temperature between the upper end thereof and the lower end. This is secured as the lower end or portion is clamped to the relatively cool body portion I and this body portion is maintained in a cool state due to the fact that very little heat can be conducted across the poor thermal joints hereinabove described and also due to the fact that the incoming secondary air cools the body portion as well as the lower portion of the control member. l

Another feature that is of great importance in contributing to the successful operation of this pilot burner even under very adverse conditions, as where natural gas is employed and where the flame tends to oat with respect to the main burner, the air intake opening or openings I4 are located at a point below this mixture zone, that is to say, at a point where fresh air alone is taken into the device, so that the pilot vflame fdl cannot be choked out although a iioating flame condition exists.

It/ is obviously possible to use other types of thermally responsive control members. For example, the ordinary type of thermostat,a fragment of which is shown in Figure 4, may be used or any other suitable type. For example, the type in which a copper tube 2|, see Flgure`4,

`is employed and carries a rod 22 having substantially zero or a very low coeicient of expansion may be used. This control member` would then merely replace the control member 3 hereinbefore described. Obviously the invention is not limited to the particular type of control member employed.

In the event that the heating value of the gas is relatively low, it is clear that it would be desirable to have the control member adjusted fairly high, that is to say, having its upper end projecting up a little greater distance into the pilot flame, whereas if the gas produced a very hot pilot flame, it is clear that the control member would preferably be slightly lowered. The

exact adjustment is easily obtained as means are provided for affording the vertical adjustment needed.

In the event that it is' desired to clean or inspect the apparatus, it is a very simple matter to do so as all that is necessary is to freely bodily lift the burner shell from the remainder of the apparatus and thereafter the composite nozzle is exposed and is easily cleaned. Also if it is desired, the composite nozzle may be readily removed from the body portion for cleaning or inspection. These parts may be readily replaced and all of this may be done without disturbing the control member. When the burner shell is replaced, it is obvious that the notch I9 cooperating with the control member will insure the proper alignment of the aperture I3 with the control member.

Further it will be seen that the device consists of a very small number of easily made parts, and that it may be quickly assembled and therefore may be manufactured at a minimum of expense.

Actual tests of the device under widely varying gas pressures and both with artificial and natural gas having widely diierent B. t. u. content and also under the condition in which a floating flame occurred, have shown that the pilot burner functions eiiiciently under all of these adverse conditions, and also it has been found that the sudden concussionat the time the main burner is lighted does not affect the pilot light at all. Tests providing artificial conditions in which a relatively violent explosion occurred have failed wholly to extinguish the pilot light. Also tests in which the floating of the flame was very pronounced indeed, coupled with explosive conditions and other artificially produced adverse conditions have not extinguished the pilot light or interfered with its correct operation.

It will be seen, therefore, that a simple reliable and highly effective pilot light has been provided by this invention which provides the maximum of safety and also which is substantially fool proof and is reliable in its operation.

The expression burner shell is intended to mean any member that cooperaties with the nozzle and receives fuel from the nozzle and has an outlet, and is not to be understood as otherwise limited unless so defined in the claims. Further, the expression concussion cup is not intended to be limited to a circular cup, as this member or portion may take many shapes and still function in the manner of a concussion cup.

Although this invention has been described in considerable detailit is to be understood that such description is intended as illustrative rather than limiting, asthe invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. A pilot burner construction comprising a. pilot burner having a fuel nozzle and a burner shell, said shell being removable from said nozzle, a thermally responsive control member, said burner shell having an air inlet and a mixture outlet, and means for aligning the mixture outlet with the said control member.

2. A pilot burner construction comprising a body portion, a pilot burner including a nozzle carried by said body portion and removable therefrom and a removable burner shell. and a thermally responsive member vertically adjustably carried by said body portion, said burner shell having a mixture outlet and an air inlet, and means for aligning the mixture outlet of said pilot burner with respect to said control member, .whereby said control member may be adjusted vertically with respect to the said pilot burner and whereby said shell and nozzle may be removed from said body portion without disturbing the adjustment of said control member.

3. In a device of the class described, a main burner, a pilot'burner construction comprising a body portion, a nozzle carried by said body portion, a burner shell supported from said body portion, said burner shell having an air inlet and a mixture outlet, said air inlet being located below the mixture zone from said main burner, and a thermally responsive control member supported from said body portion and normally heated from said pilot burner, whereby said pilot burner will not be extinguished when the iiame from said main burner floats, said control member being out of contact with the flame from said main burner, whereby said control member will be controlled from said pilot burner.

.4. A pilot burner construction comprising a body portion, a combined nozzle and Bunsen mixture forming member supported from said body portion, a burner shell supported from said body portion and having a mixture outlet communicating with the mixture outlet of said combined nozzle and mixture forming member, said shell having a poor thermal connection with said nozzle and mixture forming member, and a thermally responsive control member supported from said body portion, said control member being adjustable from said body portion without disturbing the pilot burner and being carried directly by said body portion, whereby the heat conduction to said control member will be minimized.

5. A pilot burner construction comprising a body portion, a combined nozzle and Bunsen mixture forming member supported from said body portion, a burner shell supported from said body portion and having a mixture outlet communicating with the mixture outlet of said combined nozzle and mixture forming member, said shell having a poor thermal connection with said nozzle and mixture forming member, and a thermally responsive control member supported from said body portion, said control member being adjustable from said body portion without disturbing the pilot burner and being carried directly by said body portion, whereby the heat conduction to said control member will be minimized, and said burner shell being freely removable with respect to said nozzle-and mixture forming member to expose said nozzle and mixture forming member without disturbing the adjustment of said control member.

6. A pilot burner construction comprising a body portion, a nozzle and a burner shell supported from said body portion, and a thermally responsive control member supported from said body portion, said burner shell having a concussion cup directed towards the control member and having an air inlet and a. mixture outlet located in said concussion cup.

7. A pilot burner construction comprising a body portion, a nozzle and a burner shell supported from said body portion, and a thermally responsive control member supported from said body portion, said burner shell having a concussion cup directed towards the control member and having an air inlet and a mixture outlet located in said concussion cup, said burner shell being freely removable and having means f or centering the outlet in line with the control member.

8. A pilot burner construction comprising a body portion, a nozzle and a burner shell supported from said body portion, and a thermally responsive control member supported from said body portion, said burner shell having a concussion cup directed towards the control member, said concussion cup having an air inlet and a mixture outlet and having means interlocking with said control member for aligning the outlet with said control member.

9. A pilot burner construction comprising a body portion, a. nozzle and a burner shell supported from saidl body portion, and a thermally responsive control member supported from said body portion, said burner shell having a concussion cup directed towards thecontrol member, said concussion cup having an air inlet and a mixture outlet and having means interlocking with said control member for aligning the outlet with said control member, said control member being adjustably carried from said body portion and being vertically adjustable without interfering with the interlocking of said burner shell with said control member.

10. In a device of the class described, a main burner, a Bunsen pilot burner having primary air intake means in the same zone as the secondary air for the pilot flame, a thermally responsive control member intermediate said main burner and said pilot burner and spaced from both burners, said pilot burner having a normal pressure pilot flame substantially spanning the distance between said main burner and said pilot burner vand impinging upon said -thermally responsive control member, said pilot burner having an abnormal pressure curved flame, and said thermally responsive control member becoming inoperative upon the occurrence of said abnormal pressure curved llame.

` A. GAUGER. 

